The noble caste was in the beginning always the barbarian caste: their superiority lay, not in their physical strength, but primarily in their psychical - they were more complete human beings.
It is some fundamental certainty which a noble soul has about itself, something which is not to be sought, is not to be found, and perhaps, also, is not to be lost. The noble soul has reverence for itself.
Those who recognize the existence of suffering, its cause, its remedy, and its cessation, have fathomed the four noble truths. They will walk in the right path.